439, The Galactic Center: a Window to the Nuclear Environment of Disk Galaxies

Page:

456

Authors:

Nobukawa, M.; Koyama, K.; Tsuru, T. G.; Ryu, S. G.

Abstract:

The K-shell emission line of neutral iron from the Galactic center
region was firstly discovered with
ASCA. Since then, the origin is one of the key issues for the structure
and activity of the Galactic center. Two possible origins have so far
been proposed; fluorescence due either to an X-ray or an electron
irradiations. Since the cross sections of these two processes depend
differently on the atomic number, detections of neutral Kα lines from
other elements such as sulfur, argon, calcium, chrome and manganese atoms would
provide key information for the origin. We report the Suzaku
discovery of Kα lines of neutral sulfur, argon, calcium, chrome, and
manganese atoms from the molecular cloud which emits the brightest neutral iron line.
New constrains on the origin of the neutral K-shell
lines are given with the combination of these neutral Kα lines.